1 L containing 7.8 g NaOH

1 L containing 7.8 g NaOH

 

 

Determine the hydrogen ion concentrations and pOH

in 1 L of an aqueous solution

containing 7.8 g of dissolved sodium hydroxide.

 

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NaOH의 몰질량 = 40.00 g/mol 이므로,

7.8 g / (40.00 g/mol) = 0.195 mol NaOH

( 참고 https://ywpop.tistory.com/7738 )

 

 

 

몰농도 = 용질 mol수 / 용액 L수

( 참고 https://ywpop.tistory.com/3222 )

 

= 0.195 mol / 1 L

= 0.195 M NaOH

= 0.195 M OH^-

( 참고 https://ywpop.tistory.com/12474 )

 

 

 

Kw = [H^+][OH^-] = 1.0×10^(-14)

( 참고 https://ywpop.tistory.com/2706 )

 

[H^+] = (1.0×10^(-14)) / 0.195

= 5.13×10^(-14) M

 

 

 

pOH = –log[OH^-]

= –log(0.195)

= 0.71

 

 

 

 

Determine the pH and hydroxide ion concentration

in 1 L of an aqueous solution

containing 7.8 g of dissolved sodium hydroxide.

 

pH + pOH = 14 이므로,

pH = 14 – 0.71 = 13.29

 

또는

pH = –log[H^+]

= –log(5.13×10^(-14)) = 13.29